1. Field of the Invention
The invention relates to an auto focus (AF) adjusting apparatus of a lens replaceable camera, and a camera system, and more particularly to apparatuses and methods where AF is performed by correcting a location error of a focus lens due to a difference between a frequency band used to determine an AF location and a frequency band for determining an improved location of an image surface of an imaging lens.
2. Description of the Related Art
Many image photographing apparatuses, such as cameras and camcorders, automatically focus on a subject in order to clearly capture a still image or a moving picture. Examples of an auto focusing method for automatically adjusting a focal point may include a contrast auto focusing (AF) method and a phase difference AF method.
The contrast AF method includes obtaining a contrast value with respect to an image signal generated by an imaging sensor while changing a location of a focus lens during a photographing process, and then driving the focus lens to a position where the contrast value is maximized.
The phase difference AF method uses a separate sensing device, apart from an imaging sensor, and includes detecting a focal point location from a phase difference of light applied to the sensing device.
Auto focusing is an important feature for users of image photographing apparatuses because of the convenience it provides.